Vesto Melvin Slipher

Slipher, Vesto Melvin (slĪˈfər) [key], 1875–1969, American astronomer, b. Mulberry, Ind. From 1901 he was at Lowell Observatory, Flagstaff, Ariz., where he served as director (1917–54). Much of his attention was devoted to the investigation of astronomical spectroscopy, in particular to the rotations and atmospheres of planets and nebulae. His major contribution was determining that the spectra of the vast majority of external galaxies had red shifts. This crucial discovery laid the foundation for Hubble's law and the theory of the expansion of the universe. His brother, Earl C. Slipher, 1883–1964, was a noted planetary astronomer who also worked at the Lowell Observatory. His many years of observations of the planet Mars were published in 1962 as The Photographic Story of Mars.